This application relates to an impeller having blades which run perpendicularly to a rotational axis with a feature extending from the blades to a hub.
High speed centrifugal pumps include any number of configurations. One configuration has a plurality of straight blades extending from an outer periphery of an impeller radially inwardly, and perpendicularly to a rotational axis of the impeller. In these pumps, the blades typically end at a location radially spaced from a hub, or inner shroud.
Cavitation can occur at the location between the radially inner end of the blades, and an outer periphery of the hub. Cavitation in high speed centrifugal pumps is difficult to prevent, but has been addressed by modifying an inlet case geometry, or the housing. In addition, an inducer may be provided upstream of the impeller, and serves to direct the pump fluid flow toward the impeller blades. The inducer design may be changed to address cavitation. In addition, the corners of the blades have sometimes been rounded.
The interaction between the straight impeller blades and the flow entering the impeller at a given operating point may create cavitation even with all of the above-referenced attempts. Cavitation is undesirable, and can result in vapor formation, and flow collapse, and can cause damage to the impeller.